diff --git a/tools/test-js-with-node b/tools/test-js-with-node
index 8d4ab4630c..b6d4a50e6d 100755
--- a/tools/test-js-with-node
+++ b/tools/test-js-with-node
@@ -234,7 +234,6 @@ EXEMPT_FILES = make_set(
         "web/src/todo_widget.js",
         "web/src/topic_list.js",
         "web/src/topic_popover.js",
-        "web/src/topic_zoom.js",
         "web/src/tutorial.js",
         "web/src/types.ts",
         "web/src/typing.js",
diff --git a/web/src/click_handlers.js b/web/src/click_handlers.js
index 8d7496ebc5..2c5d7c0cc4 100644
--- a/web/src/click_handlers.js
+++ b/web/src/click_handlers.js
@@ -41,7 +41,6 @@ import * as starred_messages_ui from "./starred_messages_ui";
 import * as stream_list from "./stream_list";
 import * as stream_popover from "./stream_popover";
 import * as topic_list from "./topic_list";
-import * as topic_zoom from "./topic_zoom";
 import * as ui_util from "./ui_util";
 import {parse_html} from "./ui_util";
 import * as user_topics from "./user_topics";
@@ -730,8 +729,8 @@ export function initialize() {
             );
             const scroll_position = $left_sidebar_scrollbar.scrollTop();
 
-            if (topic_zoom.is_zoomed_in()) {
-                topic_zoom.zoom_out();
+            if (stream_list.is_zoomed_in()) {
+                stream_list.zoom_out();
             }
 
             // This next bit of logic is a bit subtle; this header
diff --git a/web/src/hotkey.js b/web/src/hotkey.js
index 6f55746ce0..2a573eeeaf 100644
--- a/web/src/hotkey.js
+++ b/web/src/hotkey.js
@@ -52,7 +52,6 @@ import * as stream_data from "./stream_data";
 import * as stream_list from "./stream_list";
 import * as stream_popover from "./stream_popover";
 import * as stream_settings_ui from "./stream_settings_ui";
-import * as topic_zoom from "./topic_zoom";
 import * as unread_ops from "./unread_ops";
 import * as user_card_popover from "./user_card_popover";
 import * as user_group_popover from "./user_group_popover";
@@ -349,8 +348,8 @@ export function process_escape_key(e) {
         return true;
     }
 
-    if (topic_zoom.is_zoomed_in()) {
-        topic_zoom.zoom_out();
+    if (stream_list.is_zoomed_in()) {
+        stream_list.zoom_out();
         return true;
     }
 
diff --git a/web/src/stream_list.js b/web/src/stream_list.js
index fdd290fcf3..0755b30ec2 100644
--- a/web/src/stream_list.js
+++ b/web/src/stream_list.js
@@ -23,14 +23,70 @@ import * as stream_data from "./stream_data";
 import * as stream_list_sort from "./stream_list_sort";
 import * as sub_store from "./sub_store";
 import * as topic_list from "./topic_list";
-import * as topic_zoom from "./topic_zoom";
 import * as ui_util from "./ui_util";
 import * as unread from "./unread";
 
+let pending_stream_list_rerender = false;
+let zoomed_in = false;
+
 export let stream_cursor;
 
 let has_scrolled = false;
 
+export function is_zoomed_in() {
+    return zoomed_in;
+}
+
+function zoom_in() {
+    const stream_id = topic_list.active_stream_id();
+
+    popovers.hide_all();
+    pm_list.close();
+    topic_list.zoom_in();
+    zoom_in_topics({
+        stream_id,
+    });
+
+    zoomed_in = true;
+}
+
+export function set_pending_stream_list_rerender(value) {
+    pending_stream_list_rerender = value;
+}
+
+export function zoom_out() {
+    if (pending_stream_list_rerender) {
+        update_streams_sidebar(true);
+    }
+    const $stream_li = topic_list.get_stream_li();
+
+    popovers.hide_all();
+    topic_list.zoom_out();
+    zoom_out_topics();
+
+    if ($stream_li) {
+        scroll_stream_into_view($stream_li);
+    }
+
+    zoomed_in = false;
+}
+
+export function clear_topics() {
+    const $stream_li = topic_list.get_stream_li();
+
+    topic_list.close();
+
+    if (zoomed_in) {
+        zoom_out_topics();
+
+        if ($stream_li) {
+            scroll_stream_into_view($stream_li);
+        }
+    }
+
+    zoomed_in = false;
+}
+
 export function update_count_in_dom(
     $stream_li,
     stream_counts,
@@ -197,7 +253,7 @@ export function build_stream_list(force_rerender) {
         elems.push(sidebar_row.get_li());
     }
 
-    topic_zoom.clear_topics();
+    clear_topics();
     $parent.empty();
 
     const any_pinned_streams =
@@ -491,17 +547,17 @@ function set_stream_unread_count(
 }
 
 export function update_streams_sidebar(force_rerender) {
-    if (!force_rerender && topic_zoom.is_zoomed_in()) {
+    if (!force_rerender && is_zoomed_in()) {
         // We do our best to update topics that are displayed
         // in case user zoomed in. Streams list will be updated,
         // once the user zooms out. This avoids user being zoomed out
         // when a new message causes streams to re-arrange.
         const filter = narrow_state.filter();
         update_stream_sidebar_for_narrow(filter);
-        topic_zoom.set_pending_stream_list_rerender(true);
+        set_pending_stream_list_rerender(true);
         return;
     }
-    topic_zoom.set_pending_stream_list_rerender(false);
+    set_pending_stream_list_rerender(false);
 
     build_stream_list(force_rerender);
 
@@ -624,7 +680,7 @@ export function update_stream_sidebar_for_narrow(filter) {
     const stream_id = info.stream_id;
 
     if (!stream_id) {
-        topic_zoom.clear_topics();
+        clear_topics();
         return undefined;
     }
 
@@ -637,7 +693,7 @@ export function update_stream_sidebar_for_narrow(filter) {
         // stopped appearing from March 2018 until at least
         // April 2020, so if it appears again, something regressed.
         blueslip.error("No stream_li for subscribed stream", {stream_id});
-        topic_zoom.clear_topics();
+        clear_topics();
         return undefined;
     }
 
@@ -651,7 +707,7 @@ export function update_stream_sidebar_for_narrow(filter) {
     $stream_li.addClass("stream-expanded");
 
     if (stream_id !== topic_list.active_stream_id()) {
-        topic_zoom.clear_topics();
+        clear_topics();
     }
 
     topic_list.rebuild($stream_li, stream_id);
@@ -668,7 +724,7 @@ export function handle_narrow_activated(filter) {
 
 export function handle_message_view_deactivated() {
     deselect_stream_items();
-    topic_zoom.clear_topics();
+    clear_topics();
 }
 
 function focus_stream_filter(e) {
@@ -711,6 +767,20 @@ export function initialize({on_stream_click}) {
     update_subscribe_to_more_streams_link();
     initialize_stream_cursor();
     set_event_handlers({on_stream_click});
+
+    $("#stream_filters").on("click", ".show-more-topics", (e) => {
+        zoom_in();
+
+        e.preventDefault();
+        e.stopPropagation();
+    });
+
+    $(".show-all-streams").on("click", (e) => {
+        zoom_out();
+
+        e.preventDefault();
+        e.stopPropagation();
+    });
 }
 
 export function set_event_handlers({on_stream_click}) {
diff --git a/web/src/topic_zoom.js b/web/src/topic_zoom.js
deleted file mode 100644
index 248c2032bf..0000000000
--- a/web/src/topic_zoom.js
+++ /dev/null
@@ -1,79 +0,0 @@
-import $ from "jquery";
-
-import * as pm_list from "./pm_list";
-import * as popovers from "./popovers";
-import * as stream_list from "./stream_list";
-import * as topic_list from "./topic_list";
-
-let pending_stream_list_rerender = false;
-let zoomed_in = false;
-
-export function is_zoomed_in() {
-    return zoomed_in;
-}
-
-function zoom_in() {
-    const stream_id = topic_list.active_stream_id();
-
-    popovers.hide_all();
-    pm_list.close();
-    topic_list.zoom_in();
-    stream_list.zoom_in_topics({
-        stream_id,
-    });
-
-    zoomed_in = true;
-}
-
-export function set_pending_stream_list_rerender(value) {
-    pending_stream_list_rerender = value;
-}
-
-export function zoom_out() {
-    if (pending_stream_list_rerender) {
-        stream_list.update_streams_sidebar(true);
-    }
-    const $stream_li = topic_list.get_stream_li();
-
-    popovers.hide_all();
-    topic_list.zoom_out();
-    stream_list.zoom_out_topics();
-
-    if ($stream_li) {
-        stream_list.scroll_stream_into_view($stream_li);
-    }
-
-    zoomed_in = false;
-}
-
-export function clear_topics() {
-    const $stream_li = topic_list.get_stream_li();
-
-    topic_list.close();
-
-    if (zoomed_in) {
-        stream_list.zoom_out_topics();
-
-        if ($stream_li) {
-            stream_list.scroll_stream_into_view($stream_li);
-        }
-    }
-
-    zoomed_in = false;
-}
-
-export function initialize() {
-    $("#stream_filters").on("click", ".show-more-topics", (e) => {
-        zoom_in();
-
-        e.preventDefault();
-        e.stopPropagation();
-    });
-
-    $(".show-all-streams").on("click", (e) => {
-        zoom_out();
-
-        e.preventDefault();
-        e.stopPropagation();
-    });
-}
diff --git a/web/src/ui_init.js b/web/src/ui_init.js
index a645cddacb..d9070ab6da 100644
--- a/web/src/ui_init.js
+++ b/web/src/ui_init.js
@@ -124,7 +124,6 @@ import * as timerender from "./timerender";
 import * as tippyjs from "./tippyjs";
 import * as topic_list from "./topic_list";
 import * as topic_popover from "./topic_popover";
-import * as topic_zoom from "./topic_zoom";
 import * as transmit from "./transmit";
 import * as tutorial from "./tutorial";
 import * as typeahead_helper from "./typeahead_helper";
@@ -713,7 +712,6 @@ export function initialize_everything() {
             );
         },
     });
-    topic_zoom.initialize();
     drafts.initialize();
     drafts_overlay_ui.initialize();
     sent_messages.initialize();